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    <title>Document</title>
    <script>
        function Person () {
            // this.sayHi = function () {
            //     console.log('hi');
            // }
        }
        Person.prototype.sayHi = function () {
            console.log('hi');
        }
        var p1 =new Person();
        //p1.sayHi();
        var p2 =new Person();
        //p2.sayHi();



        p1.__proto__.sayHi();
        p2.__proto__.sayHi();
        console.log(p1.__proto__.sayHi == p2.__proto__.sayHi);
        
        console.log(p1.sayHi == p2.sayHi);//true
        
    </script>
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